Sauropods were an category of large, four-legged, herbivorous dinosaurs. They had long necks, small heads with blunt teeth, and a small brain. Picture: Hombre D Hojalata

Sibirosaurus IS a new species, experts claim: 100-million-year-old dinosaur weighed 50 tonnes and was as long as a cricket pitch

The new species of giant dinosaur that lived 100 million years ago belonged to a group that included some of the largest to roam the Earth. Related to the Titanosaur, its fossils have been painstakingly dug from Kemerevo region over recent years.

It is expected that Siberian researchers will publish full details in science journals in the coming months, when it will also be given its official Latin name. For now a few key measurements of the world's newest dinosaur have become known.

The 'very large herbivore' was an adult and weighed in at 50 tonnes. It is unclear if it was male or female. But in size it was about 20 metres long, revealed scientists at Tomsk State University.

By no means the biggest Jurassic giant, it was still a mighty beast. It was as heavy as seven full grown African male elephants - the largest modern land animals - or eight extinct Siberian woolly mammoths.

It thundered across Siberia in the Early Cretaceous Period around 100 million years ago and its remains were found in a dinosaur necropolis on the banks of the River Kiya near the village of Shestakovo.

The first relics of the skeleton were unearthed in 2008, but it has taken eight years to remove the monster's fossils from the cliff face in Kemerovo region: yet the prize is seen as highly significant, confirming a new kind of dinosaur.

The giant is being partially reconstructed in Tomsk, although scientists are not yet ready to show their full work to the world. A model is being made to highlight what it would have looked like.

'We knew immediately that we had found bones of a very large herbivorous dinosaur, but as they were locked inside blocks of sandstone, it took us years to take them out,' explained Stepan Ivantsov, of the Laboratory for Mesozoic and Cenozoic Continental Ecosystems at Tomsk State University.

'With Alexander Averianov, our colleague from the Zoological Institute of the Russian Academy of Sciences, we did comparative analyses with Titanosaurs found in other countries.'

The scientists see their discovery as a new member of the Titanosaurs, a diverse group of lizard-footed sauropod dinosaurs. They argue the skeleton is different to anything previously known.

Professor Averianov said: 'One opinion is that Titonasaurus dinosaurs could go up on their hind legs, leaning on their tails so that they could reach the higher branches of trees. To do this, they needed a more mobile rear part of the spine.'

Uniquely, the new dinosaur's sacral ribs were arranged in a 'star shape' and converged towards the centre, with no joint on the vertebral neural arch.

Its remains were found in a dinosaur necropolis onthe banks of the River Kiya near the village of Shestakovo,Kemerovo region. Pictures: TSU

The scientists have already joined the largest bones that once made its sacrum. Neck vertebrae and shoulder blades were assembled, too, from multiple pieces.

A sculptor is working on the best preserved part of the dinosaur so that later it can be exhibited to public. Sauropods were an category of large, four-legged, herbivorous dinosaurs.

They had long necks, small heads with blunt teeth, and a small brain. Their long tails counterbalanced their necks. They had large guts, necessary for digesting huge amounts of plant material.

They walked slowly on four short, thick, five-toed legs. Their nostrils were located on the upper parts of their skulls, close to the eyes.

Research has been conducted by Tomsk State University, St Petersburg State University and the Zoological Institute of the Russian Academy of Sciences.